The fiber world really does have a language of its own! For example, it's easy to confuse specific terms for how yarn is packaged. Large manufacturers usually produce their yarns in a "skein", which is cylindrical in shape, with the label wrapped around the middle. You do not have to unwind a skein and roll or wind it into a ball; you can use it as is by either unraveling the yard from the outside yarn end or finding the beginning end inside the center of the skein and pulling it out.
Smaller manufacturers and hand spinners usually wrap their yarn into "hanks." A hank is made up of long loops of yarn that are then folded and twisted together. Do NOT try to use a hand of yarn as is, it will soon become a tangled mess. It must be wound into a ball of yarn first, either by hand or with a "swift" and ball winder (more on those items later). If you don't have access to a swift and ball winder (many local yarn shops will provide access for purchased yarns), you can untwist the hank and place the loops of yarn on the back of a chair, around someone else's arms, or around your own feet while sitting on the floor (makes for a great hamstring stretch!) and manually unwind the loops and wind into a ball.